A mathematical model was elaborated by the authors for the description of the behavior of dissolved and solid cadmium in the Sajo river. The model is based on transport-equations supplemented by transitions between dissolved and stable phases and has three state variables - concentration in dissolved state, concentration in stable state, and volume of stable pollutants accumulated in the sediment. Characteristics of water motion were determined by a hydrodynamic model unit built up from the one-dimensional format of equations of impulse response and concentration of mass. The non-steady hydrodynamic model is then numerically solved by use of the implicit method of the finite differences. Instead of the usual algorithms for the solution of the system of equations, the 'double sweep' method was used for faster computer runs. An example was presented to verify that an 'identical solution' was produced with shorter computer time than used by the usual method of characteristics. After the transport equations were numerically solved the authors applied the method of partitioning. Convective and diffusive problems were separately handled. To solve the convective equation, the Lux-Wendroff scheme was used. In a second step, diffusive equations were approximated by a three-point explicit scheme.
|Number of pages||20|
|Publication status||Published - Dec 1 1985|
ASJC Scopus subject areas
- Water Science and Technology